A little background. I am well educated in this field and a long term athlete who while working at GNC has tried basically every supplement under the sun.
Now then, on to the point. The idea of a super critical post-workout window where a specific blend of macronutrients should be consumed made sense to me for a while - one needs to fuel the repairs of what has just been broken. There needs to be an influx of nutrients, namely protein, in order to repair damaged muscle tissue. Then I began hearing that raising insulin levels can in fact increase the rate of muscle protein synthesis. In addition, muscle glycogen stores would be more quickly restored. All of this would help a person avoid the dreaded catabolic meltdown (that some seem to believe, as I did, this can happen within an hour of walking out of the gym).
Then I went so school for nutrition science. With digestion rates and the slow and steady assimilation of nutrients in the human body, hours will go by after eating before the stream of amino acids and glucose stops. With the multiple meals a day we eat, chances are you are still experiencing nutrient uptake at the gym and quite possibly even after. Don't get me wrong, I love me some BCAAs but that has more to do with me liking the flavor - they are just a drop in the bucket at most.
So you finished your routine, you speed past the bathroom because you forgot your whey hydrolysate shake mixed with dextrose and maltodextrin at home. Assuming you had eaten in the last three to four hours, you would have nearly wet yourself for nothing. The carbohydrates will do next to nothing as far as muscle growth/repair (refer to studies at the bottom) and as far as waxy maize or fractionated barley and all that, it has never increased my insulin response more than dextrose. I know this because I am type 1 diabetic and have tested blood sugars (which would otherwise trigger a release of insulin) at similar intervals after ingesting all these 'super carbs' without noting a real difference. Beyond this, there is no super short term spike in insulin. Once released in a healthy person, it is often broken down after an hour of circulation. As for hydrolysates, what a waste of money. I certainly am not saying skip a post workout meal all together or even a whey shake as the interval between meals may be growing to the point where catabolism may start taking place, but it sure as hell doesn't begin as quickly as many people think.
Beyond this, the so-called "anabolic window" is critical during the entire period which muscle tissue needs repair.
Your muscle tissue undergoes repairs for days and is constantly in need of materials such as amino acids to make said repairs. Glycogen stores need to be refilled and again this is not at all critical immediately post workout or even during (this is obviously different for endurance athletes). You can slam down the highest quality shakes in the world and eat the cleanest meals possible for an entire day and make no gains at all if the day after doesn't provide continued supplies of nutrients and calories.
Here is another post with some incredibly insightful studies borrowed from a user on another forum named 'alan aragon'.
Hierarchy of Importance
When speaking of nutrition for improving body composition or training performance, it's crucial to realize there's an underlying hierarchy of importance. At the top of the hierarchy is total amount of the macronutrients by the end of the day. Distantly below that is the precise timing of those nutrients. With very few exceptions, athletes and active individuals eat multiple times per day. Thus, the majority of their day is spent in the postprandial (fed) rather than a post-absorptive (fasted) state. The vast majority of nutrient timing studies have been done on overnight-fasted subjects put through glycogen depletion protocols, which obviously limits the applicability of the outcomes. Pre-exercise (and/or during-exercise) nutrient intake often has a lingering carry-over effect into the post-exercise period. Throughout the day, there's a constant overlap of meal digestion & nutrient absorption. For this reason, the effectiveness of nutrient timing does not require a high degree of precision.
The Primary Laws of Nutrient Timing
The First Law of Nutrient Timing is: hitting your daily macronutrient targets is FAR more important than nutrient timing.
The Second Law of Nutrient Timing is: hitting your daily macronutrient targets is FAR more important than nutrient timing.
NOTE: Please do not misinterpret the above to mean that timing is irrelevant. On the contrary, it's very relevant. Timing just happens to have MUCH LESS impact on results than hitting your macro totals for the day. This doesn't diminish the fact that people need to individualize their meal timing so that it maximizes their training performance (& does not hinder it). The latter manipulations vary widely, because people have different training protocols, goals, and tolerances. For example, some people experience their best training performance in an immediately fed state, while others do best in a semi-fasted or fasted state. Endurance athletes who neglect carbohydrate timing will not optimize their training capacity. Strength/power athletes with minimal endurance demands have much
less of a concern for this. There's no way to 'universalize' a nutrient timing prescription that applies to everyone & all types of athletes. But to reiterate, macro totals for the day overshadow timing in terms of importance, especially for bodybuilding. If macro totals for the day are not hit, the most precisely neurotic timing of meals is all for poo.
For the technically inclined:
Nutrient timing revisited: is there a post-exercise anabolic window?
Same paper in PDF: http://www.jissn.com/content/pdf/1550-2783-10-5.pdf
Lastly, I am not saying supplements aren't helpful. I use them plenty and they make my life a little easier and a lot more fun. I just think it's ridiculous that so many lose sight of the fact that supplements are just that - supplements. I remember just recently reading someone say something to this effect: 'I used to worry about the nutrient timings and micromanage every feeding interval but it was when I put that energy into lifting and just making sure I hit my macros that the gains came".